Forming Tool and Method

ABSTRACT

A method and a tool arrangement for deforming at least one section of a less precisely positioned body by such an amount that the section to be deformed lies in a more precisely defined position with respect to the body. A tool arrangement includes at least one retaining device and at least one forming die moveable in the direction of the retaining device. The section ( 28 ) to be deformed is arranged between the retaining device and the forming die. In order to improve the quality of the deformed body, the deforming movement of the forming die is controlled depending on the position of the forming die without fixed counterpart holder in a controlled manner such that the forming die is stopped in a defined final position. With the tool arrangement, a drive for the forming die is coupled to a control device such that the deforming movement of the forming die is controlled depending on the position of the forming die, without a fixed counterpart holder, in a controlled manner such that the forming die is stopped in a defined final position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for deforming at least one section on a less precisely positioned body by such an amount that the section to be deformed lies in a more precisely defined position with respect to the body. The invention includes a tool arrangement that has at least one retaining device and at least one forming die movable in the direction of the retaining device. The section to be deformed is arranged between the retaining device and the forming die, with the following steps: the retaining device is positioned at the section to be deformed; and the section to be deformed is deformed by a movement of the forming die in the direction of the retaining device, according to the preamble of claim 1.

The invention also relates to a tool arrangement for carrying out the method described above, with at least one retaining device and at least one forming die moveable in the direction of the retaining device. The section to be deformed is arranged between the retaining device and the forming die, according to the preamble of claim 5.

2. Discussion of Background Information

A method for deforming at least one section on a less precisely positioned body by such an amount that its surface lies in a more precisely defined position with respect to the body is known from German printed patent specification DE 36 42 900 C2. The known deforming method is carried out by a moveable retaining device that has at least one fixed counterpart holder, holding mechanism moveable and lockable with respect thereto and at least one form block moveable in the direction of the counterpart holder or counterpart holders. The counterpart holder or counterpart holders, and the holding mechanism are provided facing the first surface of the body and the form block or form blocks opposite them are provided facing the second surface of the body. The known method has the following steps: exact positioning of the counterpart holder or counterpart holders in the area of the section or sections to be deformed above the first surface of the body; then placing the holding mechanism against the first surface of the body in this area; subsequently locking the holding mechanism in this position and bringing it into contact, and finally a forming movement of the form block or form blocks until they bear against the surface(s) of the section or sections to be deformed on or at the counterpart holders.

Unexamined German application DE 199 27 101 A1 discloses a method for mechanically joining two flat parts to be joined by clinching without a cutting component by an active die with a linear, striking or wobbling motion, a counterpunch, a fixed or moveable female die and a holding-down clamp to prestress the parts to be joined while forming a neck area and an undercut area. The known method is characterized in that the counterpunch already comes into active contact with the part to be joined on the female die side before, during or immediately after the start of the clinching operation and thus is used to compress the two parts to be joined, so that, due to the reduced ironing, the part to be joined on the male die side forms a thicker neck area and more material is forced out of both parts to be joined from the subsequent base area through the compression in the neck area and the undercut area.

German printed patent specification DE 197 47 167 C2 discloses a method for the perforated joining of sheet-metal parts lying flat one upon the other, in which sheet-metal parts are jointly displaced out of the sheet-metal plane and squeezed under the action of a deformation energy by a tool set comprising a male die and a female die having an anvil. The known method is characterized in that the deformation energy is fed through several impulses to a mass striking the tool set in an accelerated manner.

German printed patent specification DE 195 24 164 C1 discloses a method for positioning ready-shaped plate press parts and a robot-guided tool and the production of screw connection points on ready-shaped plate press parts of a vehicle bodywork to compensate component part tolerances between the plate press part and a bodywork part to be connected to it and a device for carrying out the same. In order to ensure in a simple manner a precise positioning and a compensation of component part tolerances of the screw connection points on the plate press part, it is proposed for the exact actual position of the plate press part within the work space of an industrial robot in relation to it and the exact actual contour according to the circumferential course to be determined. This actual contour is compared to the stored data of a reference model and superimposed as far as possible on the plate press part to be machined.

From German printed patent specification DE 39 32 532 C2, a tool unit is known for force-intensive deformation methods with two tool elements and two pneumatic or hydraulic drives lying opposite and acting in an opposite linear manner. The known tool unit is characterized in that the two drives are housed in a common housing and are arranged outside the force application line of the two tool elements. Each tool element is held on a bracket, so that the brackets arranged opposite one another are held so as to be slidable in a linear manner along the joint housing of the drives at the same time. Each bracket is connected to the moveable part of the respective drive in a detachable manner.

SUMMARY OF THE INVENTION

The invention creates an alternative deformation method and an alternative tool arrangement to carry out the deformation method.

The invention is attained with a method that the deforming movement of the forming die is controlled in a controlled manner depending on the position of the forming die without a fixed counterpart holder such that the forming die is stopped in a defined final position. In the deformation method known from German printed patent specification DE 36 42 900 C2, the forming die is always moved out of its starting position just until the forming die with the section to be deformed bears against the counterpart holder serving as a position-defined stop. The counterpart holder forms a female die. This known method does not provide for the movement of the forming die to be influenced. In contrast, the distance-controlled deforming movement according to the invention provides the advantage that the movement of the forming die can be influenced in a targeted manner, in order, e.g., to take into account errors in positioning and/or tolerances in the thickness of the body to be deformed.

A preferred exemplary embodiment of the method is characterized in that the forming die is driven depending on the position of the forming die. It is thus possible to position the forming die exactly. The drive is preferably an electromotive or hydraulic drive that can optionally comprise a transmission.

Another preferred exemplary embodiment of the method is characterized in that the position and/or the movement of the forming die are/is detected. The position of the forming die can be detected, e.g., via a position sensing system. A position sensing system of this type preferably comprises at least one sensor device through which the position of the forming die and/or the retaining device is detected relative to the section to be deformed or relative to one another. The retaining device is preferably positioned with the aid of the position sensing system. It is thus possible to position the retaining device exactly on the body to be deformed. This can be carried out, for example, by approaching in a non-contact manner or with a contacting touch.

Another preferred exemplary embodiment of the method is characterized in that a correction value is determined which is taken into consideration in the form of an additional compensation movement by the forming die.

Furthermore, the invention is attained through a tool arrangement with the features of claim 5. The tool arrangement is characterized in that a drive for the forming die is coupled to a control device through which the deforming movement of the forming die is controlled in a controlled manner depending on the position of the forming die without fixed counterpart holder such that the forming die is stopped in a defined final position. This provides the advantage that the forming die can be positioned exactly without a fixed counterpart holder. The drive can be, e.g., an electromotive or a servo-hydraulic drive.

A preferred exemplary embodiment of the tool arrangement is characterized in that the forming die is driven by an electromotive drive. Through the electromotive drive the forming die can be stopped at any position with sufficient accuracy of position. Optionally other drive systems with sufficient positioning accuracy can also be used in the tool arrangement.

Another possible exemplary embodiment of the tool arrangement is characterized in that the forming die is driven by a hydraulic drive. This has the advantage that relatively large forces can be applied to the forming die.

Another preferred exemplary embodiment of the tool arrangement is characterized in that the control device is coupled to a sensor device that detects the position and/or the movement of the forming die and/or the retaining device. The coupling can thereby be a mechanical coupling and/or an optical coupling and/or another suitable coupling. The distance between the forming die and the body to be deformed, for example, can be detected through the sensor device. Furthermore, the distance between the retaining device and the body to be deformed can be detected through the sensor device. Moreover the distance between the forming die and the retaining device can be detected through the sensor device. Depending on the embodiment of the sensor device, it can be additionally or alternatively detected when the forming die and/or the retaining device come or comes into contact with the body to be deformed.

Another preferred exemplary embodiment of the tool arrangement is characterized in that the sensor device is integrated into the retaining device. Preferably the retaining device and the sensor device are integrated into a base structure of the tool arrangement. The structure of the tool arrangement according to the invention is thereby simplified.

Another preferred exemplary embodiment of the tool arrangement is characterized in that the retaining device comprises at least one moveable holding mechanism prestressed in the direction of the section to be deformed. The holding mechanism, which is also called a clamping holder, acts as a drawing cushion and guarantees a planar deformation surface on the body to be deformed.

Another preferred exemplary embodiment of the tool arrangement is characterized in that the sensor device is integrated into the holding mechanism. This makes it possible to reduce the movement of the retaining device as soon as or before the holding mechanism comes into contact for the first time with the body to be deformed. The slower movement of the retaining device provides the advantage that the retaining device comes to rest more gently against the body to be deformed.

Another preferred exemplary embodiment of the tool arrangement is characterized in that the sensor device is integrated into a measuring device that is moveable relative to the retaining device and is prestressed in the direction of the section to be deformed. This makes it possible to reduce the movement of the retaining device as soon as the measuring device comes into contact for the first time with the body to be deformed. The slower movement of the retaining device provides the advantage that the retaining device comes to rest more gently against the body to be deformed. This renders possible a leading, zero-force retraction of the retaining device.

Another preferred exemplary embodiment of the tool arrangement is characterized in that a stamping tool can be moved through the retaining device. With the aid of the stamping tool at least one through hole, which serves, for example, to accept an attaching mechanism, can be produced in the section to be deformed.

Another preferred exemplary embodiment of the tool arrangement is characterized in that the forming die is attached to one branch of an essentially L-shaped bracket, the other branch of which is attached to a base structure of the tool arrangement. The base structure and the bracket form deforming tongs. The retaining device and the drive for the forming die are preferably integrated into the base structure.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features and details of the invention are provided by the description below in which different exemplary embodiments are described in detail with reference to the drawing. The features mentioned in the claims and in the specification can thereby be essential for the invention in each case individually or in any combination.

The drawings show:

FIG. 1 shows a diagrammatic representation of a tool arrangement according to the invention with a forming die in its starting position;

FIG. 2 shows the tool arrangement from FIG. 1 with the forming die in the final position;

FIG. 3 shows a diagrammatic representation of a variant of the tool arrangement shown in FIGS. 1 and 2 with a moveable measuring sleeve, whereby the forming die is in its starting position; and

FIG. 4 shows the tool arrangement from FIG. 3 with the forming die in its final position.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

FIG. 1 is a diagrammatic representation of a tool arrangement 1 that comprises a base structure 3. The base structure 3 of the tool arrangement 1 is attached to a robot 4 (industrial robot) or to a robot arm so that the base structure 3 can be moved via the robot 4 in different directions in the space.

An essentially L-shaped bracket 6 is attached to the base structure 3 such that it can be moved to and fro in the direction of a double arrow 7. The bracket 6 is driven by an electromotive drive 8 that is integrated into the base structure 3 of the tool arrangement 1. The bracket 6 has a branch 16 that is arranged perpendicular to another branch 17 of the bracket 6. The free end of the branch 16 of the bracket 6 is guided on the base structure 3 of the tool arrangement 4 so as to be moveable to and fro in the direction of the double arrow 7.

An essentially circular cylindrical forming die 10 is attached rigidly, i.e., not relatively moveable, on the free end of the other branch 17 of the bracket 6. The forming die 10 extends parallel to the branch 16 of the bracket 6. A spring-preloaded clamping holder 12 is guided on the forming die 10 so as to be moveable to and fro in the axial direction of the forming die 10. The clamping holder 12 essentially has the form of a circular cylinder jacket, the inside diameter of which is slightly larger than the outside diameter of the forming die 10, so that the forming die 10 and the clamping holder 12 can be displaced relative to one another in the axial direction.

A retaining device 15 is attached to the base structure 3 of the tool arrangement 1 opposite the forming die 10. The retaining device 15 has a holder body 18 that is rigidly connected to the base structure 3. The holder body 18 has essentially the shape of a circular cylinder jacket that is arranged concentrically to the forming die 10. A measuring sensor device 20 or a measuring system is integrated into the end of the holder body 18 facing the forming die 10, which measuring system comprises contact sensors and/or distance sensors.

A spring-preloaded clamping holder 22 is mounted in the holder body 18 so as to be moveable to and fro, which clamping holder essentially has the form of a circular cylinder jacket, the outside diameter of which is smaller than the inside diameter of the holder body 18. One end of a stamping tool 24 is mounted in the clamping holder 22, the other end of which stamping tool is mounted in a stamping device 25 that is integrated into the base structure 3.

A body 27 with a section 28 to be deformed is arranged between the forming die 10 and the retaining device 15. The section 28 to be deformed has a surface 29, which faces the forming die 10, and a surface 30, which faces the retaining device 15.

In operation the tool arrangement 1, which is also called deforming tongs, is brought into the starting position shown in FIG. 1 with the aid of the robot 4. The bracket 6 with the forming die 10 can be positioned exactly in the direction of the double arrow 7 relative to the base structure 3 of the tool arrangement 1 via the electromotive drive 8 that is coupled to the integrated position sensing system 20. The tool arrangement according to the invention and the method according to the invention are used to deform the section 28 to be deformed on the less precisely positioned body 27 by such an amount that the surface 29 thereof, and thus also indirectly its surface 30, comes to rest in a precisely defined position with respect thereto.

The holder body 18 is brought into position by moving the tool arrangement 1 with the aid of the measuring system 20, which comprises distance or contact sensors, in the area of the surface 30 to be deformed of the body 27 made of sheet metal. This can be carried out on the one hand by a non-contact approach to or by a contact touching of the surface 30. Subsequently a distance-controlled sliding movement of the bracket 6 and thus of the forming die 1 is triggered towards the section 28 to be deformed up to a final position determined with the aid of the measuring system 20. A relative movement of the forming die 10 to the spring-preloaded clamping holder 12 in the axial direction thereby occurs at the same time.

FIG. 2 shows the final position of the forming die 10 determined with the aid of the position sensing system 20. FIG. 2 also shows that the holder body 18 is located resting on the surface 30 of the section 28 to be deformed. The free end of the forming die 10 is not abutting against a part of the retaining device 15. The free end of the forming die 10 is resting against only the section 28 to be deformed. The final position of the forming die 10 shown in FIG. 2 is adopted in a distance-controlled manner via the electromotive drive 8.

In order to compensate for an undesirable springing of the bracket 6 and the associated impreciseness of the deforming depth or embossing depth, a correction value can be determined based on a characteristic curve and provided as an additional embossing depth. In the deforming position of the tool arrangement 1 shown in FIG. 2, the surface 29 of the body section 28 to be deformed of the body 27 is in the defined final position. This defined final position is obtained independently of the spring-mounted clamping holder 22. The clamping holder 22 serves only as a drawing cushion that moves together with the section 28 to be deformed against the spring preloading force.

As the last process step, the section 28 deformed with positional accuracy is pierced with the aid of the stamping tool 24.

FIGS. 3 and 4 show a similar exemplary embodiment as FIGS. 1 and 2 in diagrammatic form. Identical parts are provided with identical reference numbers. In order to avoid repetition, reference is made to the earlier description of FIGS. 1 and 2. Only the differences between the two exemplary embodiments are discussed in the following.

In the exemplary embodiment shown in FIGS. 3 and 4, a measuring sleeve 40 essentially shaped like a circular cylindrical jacket is guided in a displaceable manner on the outer circumference of the holder body 18 in the axial direction against the preloading force of a spring. The spring-mounted measuring sleeve 40 comprises an integrated position sensing system with contact and/or distance sensors. The measuring sleeve 40 provides the advantage that the traversing speed of the robot 4 can be reduced as soon as the measuring sleeve 40 comes into contact with the surface 30 of the section 28 to be deformed. The robot 4 can thus be moved more slowly along the remaining traverse of the holder body 18 up to the surface 30 of the section 28 to be deformed, in order to make it possible for the rigid holder body 18 to come to rest gently against the surface 30 of the section 28 to be deformed. 

1. A method for deforming at least one section on a non-precisely positioned body by an amount that the section to be deformed lies in a more precisely defined position with respect to the body, by a tool arrangement that has at least one retaining device and at least one forming die movable in the direction of the retaining device, the section to be deformed is arranged between the retaining device and the forming die, comprising: positioning the retaining device at the section to be deformed; deforming the section to be deformed by a movement of the forming die in a direction of the retaining device, the deforming movement of the forming die being controlled in a controlled manner depending on a position of the forming die, without a fixed counterpart holder, such that the forming die is stopped in a defined final position.
 2. A method according to claim 1, wherein the forming die is driven depending on the position of the forming die.
 3. A method according to claim 1, wherein at least one of the position and the movement of the forming die is detected.
 4. A method according claim 1, further comprising detecting a correction value, which is an additional compensation movement of the forming die.
 5. A tool comprising: at least one retaining device and at least one forming die moveable in a direction of the retaining device, wherein a section to be deformed being arranged between the retaining device and the forming die; a drive for the forming die being coupled to a control device, the deforming movement of the forming die being controlled based on a position of the forming die, without a fixed counterpart holder, in a controlled manner such that the forming die is stopped in a defined final position.
 6. The tool arrangement according to claim 5, wherein the forming die is driven by an electromotive drive.
 7. The tool arrangement according to claim 5, wherein the forming die is driven by a hydraulic drive.
 8. The tool arrangement according claim 5, wherein the control device is coupled to a sensor device, which detects at least one of the position and movement of the forming die and/or of the retaining device.
 9. The tool arrangement according to claim 8, wherein the sensor device is integrated into the retaining device.
 10. The tool arrangement according to claim 5, wherein the retaining device comprises at least one moveable holding mechanism that is prestressed in a direction of the section to be deformed.
 11. The tool arrangement according to claim 10, wherein the sensor device is integrated into the holding mechanism.
 12. The tool arrangement according to claim 8, wherein the sensor device is integrated into a measuring device that is moveable relative to the retaining device and is prestressed in a direction of the section to be deformed.
 13. The tool arrangement according claim 5, further comprising a stamping tool moved through the retaining device.
 14. The tool arrangement according to claim 5, wherein the forming die is attached to a branch of an essentially L-shaped bracket, an other branch of which is mounted on a base structure of the tool arrangement.
 15. A method of deforming a section between a retaining device and a forming die, comprising: positioning the retaining device at the section to be deformed; and driving the forming die in a direction of the retaining device based on a position of the forming die.
 16. The method according to claim 15, wherein the driving is a hydraulic drive or electromotive drive.
 17. The method according to claim 15, wherein a position and/or movement of the forming die is detected relative to the section to be deformed.
 18. The method according to claim 15, further comprising determining a correction value which is taken into consideration in a form of an additional compensation movement by the forming die.
 19. The method according to claim 15, further comprising determining a distance between the retaining device and a section to be deformed.
 20. The method according to claim 15, further comprising reducing a movement of the retaining device as soon as or before a holding mechanism comes into contact for a first time with a body to be deformed. 